Constricting mechanism for use with a surgical access assembly

ABSTRACT

The present disclosure relates to a surgical access member for establishing percutaneous access to a surgical worksite within tissue. The surgical access member includes a constricting mechanism that is adapted to removably receive a surgical instrument and resiliently transition between an open state and a constricted state. In the open state, insertion of the surgical instrument through the constricting mechanism is substantially uninhibited. In the constricted state, the constricting mechanism substantially limits transverse movement of the surgical instrument, and may facilitate the creation of a substantially fluid-tight seal therewith.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.12/486,164, filed Jun. 17, 2009, which claims the benefit of andpriority to U.S. Provisional Application Ser. No. 61/081,483, filed onJul. 17, 2008, the entire contents of which are incorporated herein byreference.

BACKGROUND

1. Technical Field

The present disclosure relates generally to apparatus and methods forproviding percutaneous access to an internal worksite during a surgicalprocedure. More particularly, the present disclosure relates to aconstricting mechanism for use with a surgical access system such, as atrocar or cannula assembly, that is adapted to removably receive asurgical instrument.

2. Background of the Related Art

Minimally invasive surgical procedures are generally performed throughsmall openings in a patient's tissue, as compared to the largerincisions typically required in traditional procedures, in an effort toreduce both patient trauma and recovery time. Access tubes, such astrocars or cannulae, are inserted into the openings in the tissue, andthe surgical procedure is carried out by one or more surgicalinstruments inserted through the lumen which they provide.

In laparoscopic procedures, the patient's abdominal region is typicallyinsufflated, i.e., filled with carbon dioxide, nitrogen gas, or thelike, to raise the abdominal wall and provide sufficient working spaceat the surgical worksite. Accordingly, preventing the escape of theinsufflation gases is desirable in order to preserve the insufflatedsurgical worksite. To this end, surgical access systems generallyincorporate a seal adapted to maintain the insufflation pressure.

During the course of a minimally invasive surgical procedure, it isoften necessary for a clinician to use different surgical instrumentswhich may vary in size, e.g., diameters. Additionally, a clinician willfrequently manipulate the surgical instruments transversely, orside-to-side, in an effort to access different regions of the surgicalworksite. This transverse movement may cause the seal to deform, therebyallowing the escape of insufflation gas around the instrument.

While many varieties of seals are known in the art, there exists acontinuing need for a mechanism capable of addressing these concerns.

SUMMARY

In one aspect of the present disclosure, a surgical access device isdisclosed that is adapted for removable positioning within apercutaneous tissue tract. The surgical access device includes ahousing, a constricting mechanism positioned within the housing, and anaccess sleeve that extends distally from the housing.

The constricting mechanism includes a proximal member in mechanicalcooperation with a distal member to permit relative rotationtherebetween such that the constricting mechanism is repositionablebetween a first state and a second state. In the first state, theconstricting mechanism is adapted to permit insertion of a surgicalinstrument, and in the second state, the constricting mechanism isadapted to engage the surgical instrument to limit transverse movementthereof.

The proximal member includes a first plurality of pins extendingoutwardly therefrom and the distal member includes a second plurality ofpins extending outwardly therefrom. Each of the first and secondpluralities of pins are configured and dimensioned for engagement with aplurality of rods positioned between the proximal and distal members.The first plurality of pins and the second plurality of pins eachcorrespond in number to the number of rods. Each rod includes a boreformed at a first end and a slot formed at a second end, and each of thefirst and second pluralities of pins includes a stem portion terminatingin a head. The head of each pin defines a transverse dimension that isgreater than a transverse dimension defined by the stem portion, andeach bore and slot defines a substantially identical transversedimension that is greater than the transverse dimension defined by thestem portion of each pin, but less than the transverse dimension definedby the head of each pin, such that the pins are securely engagable withthe rods.

In one embodiment of the constricting mechanism, the plurality of firstpins are positioned within the bores of each of the plurality of rodsand the plurality of second pins are positioned within the slots of eachthe plurality of rods such that relative rotation between the proximaland distal members causes the rods to pivot about the plurality of firstpins as the plurality of second pins traverse the slots.

The rods may be arranged in an interlaced configuration to define anopening therebetween that extends through the constricting mechanism.When the constricting mechanism is in the first state, the openingdefines a first transverse dimension, and when the constrictingmechanism is in the second state, the opening defines a second, smallertransverse dimension.

In another embodiment of the constricting mechanism, at least one of thefirst and second members includes a tactile member that is configuredfor manual engagement to facilitate relative rotation between theproximal and distal members.

In yet another embodiment of the constricting mechanism, each rodincludes a scalloped portion that is configured and dimensioned toengage an outer surface of the surgical instrument.

In still another embodiment, the constricting mechanism further includesa biasing member that is in mechanical cooperation with at least one ofthe proximal and distal members to normally bias the constrictingmechanism into the second state.

Additionally, or alternatively, the constricting mechanism may include asleeve connected to the proximal and distal members and defining apassageway therethrough that is configured and dimensioned to receivethe surgical instrument. The sleeve is forced into engagement with anouter surface of the surgical instrument as the constricting mechanismis repositioned from the first state into the second state such that asubstantially fluid-tight seal is formed between the constrictingmechanism and the surgical instrument. The sleeve may be formed of aresilient material such that the passageway enlarges as the constrictingmechanism is repositioned from the second state into the first state tofacilitate removal of the surgical instrument.

In another embodiment, the constricting mechanism may further include atleast one seal member associated with at least one of the proximal anddistal members and adapted to form a substantially fluid tight seal withthe surgical instrument upon insertion.

In an alternate aspect of the present disclosure, a method ofestablishing percutaneous access to a surgical worksite is disclosed.The method includes the provision of a surgical access assembly having ahousing, a constricting mechanism positioned within the housing andincluding a proximal member in mechanical cooperation with a distalmember to permit relative rotation therebetween, and an access sleeveextending distally from the housing. The method further includes thesteps of positioning the surgical access device within tissue, insertingthe surgical instrument into the surgical access device, andeffectuating relative rotation between the proximal and distal membersof the constricting mechanism such that the constricting mechanismengages the surgical instrument to limit transverse movement thereof.

In another aspect of the present disclosure, a method of manufacturing aconstricting mechanism for use with a surgical access device to limittransverse movement of a surgical instrument inserted therethrough. Themethod includes the steps of providing a proximal member including afirst plurality of pins extending outwardly therefrom, providing adistal member including a second plurality of pins extending outwardlytherefrom, providing a plurality of rods including structure adapted toreceive one of the first plurality of pins and one of the secondplurality of pins, and positioning the rods between the proximal anddistal members such that the rods receive one of the first plurality ofpins and one of the second plurality of pins to permit relative rotationbetween the proximal and distal members. Relative rotation between theproximal and distal members repositions the constricting mechanismbetween a first state, in which the constricting mechanism is adapted topermit insertion of the surgical instrument, and a second state, inwhich the constricting mechanism is adapted to engage the surgicalinstrument to limit transverse movement thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure are described herein belowwith references to the drawings, wherein:

FIG. 1 is a side, schematic view of a surgical access assembly includingone embodiment of a constricting mechanism in accordance with theprinciples of the present disclosure;

FIG. 2 is a top, plan view of the constricting mechanism seen in FIG. 1with parts separated;

FIG. 3 is a side, plan view of the constricting mechanism seen in FIG. 1with parts separated;

FIG. 4 is an enlarged view of the section indicated in FIG. 3;

FIG. 5 is a top, schematic view of the constricting mechanism seen inFIG. 1 shown in an open state prior to the insertion of a surgicalinstrument;

FIG. 6 is a top, schematic view of the constricting mechanism seen inFIG. 1 shown in a constricted state with a surgical instrument insertedtherethrough;

FIG. 7 is a top, schematic view of another embodiment of theconstricting mechanism seen in FIG. 1;

FIG. 8 is a top, schematic view of yet another embodiment of theconstricting mechanism seen in FIG. 1 including a biasing member andshown in a constricted state;

FIG. 9 is a top, schematic view of the constricting mechanism seen inFIG. 8 shown in an open state;

FIG. 10 is a side, schematic view of still another embodiment of theconstricting mechanism seen in FIG. 1 including a tubular sleeve andshown in an open state with a surgical instrument inserted therethrough;

FIG. 11 is a top, schematic view of the constricting mechanism seen inFIG. 10 shown a constricted state;

FIG. 12 is a side, schematic view of one embodiment of the constrictingmechanism seen in FIG. 10 including a biasing member and shown aconstricted state subsequent to the insertion of a surgical instrumentthrough the tubular sleeve;

FIG. 13 is a side, schematic view of another embodiment of theconstricting mechanism seen in FIG. 1 including a seal member;

FIG. 14 is a top view of the constricting mechanism seen in FIG. 13illustrating the seal member prior to the insertion of a surgicalinstrument;

FIG. 15 is a top, schematic view of the constricting mechanism seen inFIG. 14 shown in a constricted state and illustrating the seal memberwith a surgical instrument inserted therethrough; and

FIG. 16 is a side, schematic view of one embodiment of the constrictingmechanism seen in FIG. 13 including a biasing member.

DETAILED DESCRIPTION

In the drawings and in the description which follows, in which likereferences numbers identify similar or identical elements, the term“proximal” will refer to the end of an instrument or component that isclosest to the clinician during use, while the term “distal” will referto the end that is furthest from the clinician. Additionally, use of theterm “surgical instrument” throughout the present disclosure should beunderstood to include any surgical instrument that may be employedduring the course of a minimally invasive surgical procedure, includingbut not limited to an obturator, a surgical fastening apparatus, aviewing scope, or the like. Finally, the term “transverse” should beunderstood as referring to any axis, or movement along any axis, thatintersects the longitudinal axis of an instrument or component.

FIG. 1 illustrates a surgical access assembly 1000 having a housing 1002at a proximal end 1004 thereof and an access sleeve 1006 which extendsdistally therefrom along a longitudinal axis “A”. The housing 1002 isconfigured and dimensioned to accommodate a constricting mechanism 100,which will be described in detail below, and may be any structuresuitable for this intended purpose. Further information regarding thehousing 1002 may be obtained through reference to commonly owned U.S.Pat. No. 7,169,130 to Exline et al., the entire contents of which areincorporated by reference.

The access sleeve 1006 is configured and dimensioned for positioningwith a tissue tract 10 formed in a patient's tissue “T”, which can beeither pre-existing or created by the clinician through the use of ascalpel, for example. The access sleeve 1006 defines a lumen 1008 and anopen distal end 1010 to permit the passage of one or more surgicalinstruments “I” therethrough to facilitate percutaneous access to asurgical worksite “W” removed from the patient's tissue “T” with thesurgical instrument “I”.

Referring now to FIGS. 2-6 as well, one embodiment of the constrictingmechanism 100 will be discussed. The constricting mechanism 100 includesa proximal member 102 _(A) and a distal member 102 _(B) in mechanicalcooperation such that the respective proximal and distal members 102_(A), 102 _(B) are adapted for relative rotation. The proximal anddistal members 102 _(A), 102 _(B) define respective apertures 104 _(A),104 _(B) that are configured and dimensioned to accommodate passage ofthe surgical instrument “I” therethrough. While the respective proximaland distal members 102 _(A), 102 _(B) are illustrated as substantiallyannular structures, any suitable configuration may be employed,including polygonal configurations such as triangular, square, orhexagonal. The respective proximal and distal members 102 _(A), 102 _(B)may be formed of any suitable biocompatible material, including but notbeing limited to polymeric materials.

To facilitate relative rotation between the proximal and distal members102 _(A), 102 _(B), the proximal and distal members 102 _(A), 102 _(B)include a plurality of pins 106 _(A), 106 _(B), respectively, that areengagable with a plurality of rods 108. The plurality of pins 106 _(A),106 _(B) correspond in number to the number of rods 104, andaccordingly, in the embodiment seen in FIGS. 1-6, the proximal member102 _(A) includes three pins 106 _(A) and the distal member 102 _(B)includes three pins 106 _(B) corresponding to a first rod 104 _(A), asecond rod 104 _(B), and a third rod 104 _(C). In alternate embodiments,however, the constricting mechanism 100 may include fewer or greaternumbers of pins 106 _(A), 106 _(B) and rods 108.

The pins 106 _(A) depend downwardly from the proximal member 102 _(A),i.e., towards the distal member 102 _(B), whereas the pins 106 _(B)depend upwardly from the distal member 102 _(B), i.e., towards theproximal member 102 _(A). Each of the pins 106 _(A), 106 _(B) includes astem portion 110 that terminates in a head 112. The stem portion 110defines a transverse dimension “D_(S)” and the head 112 defines atransverse dimension “D_(H)”. As best seen in FIG. 4, the transversedimension “D_(H)” defined by the head 112 is greater than the transverse“D_(S)” defined by the stem portion 110.

Each of the plurality of rods 108 _(A), 108 _(B), 108 _(C) includes abore and a slot formed at opposite ends thereof that are configured anddimensioned to receive the pins 106 _(A), 106 _(B) included on theproximal and distal members 102 _(A), 102 _(B), respectively.Specifically, the first rod 108 _(A) includes a bore 114 _(A) at a firstend 116 _(A1) and a slot 118 _(A) at a second end 116 _(A2), the secondrod 108 _(B) includes a bore 114 _(B) at a first end 116 _(B1) and aslot 118 _(B) at a second end 116 _(B2), and the third rod 108 _(C)includes a bore 114 _(C) at a first end 116 _(C1) and a slot 118 _(C) ata second end 116 _(C2). The bores 114 _(A), 114 _(B), 114 _(C) and theslots 118 _(A), 118 _(B), 118 _(C) each define a transverse dimension“D” that is greater than the transverse dimension “D_(S)” defined by thestem portion 110 of the pins 106 _(A), 106 _(B), but less than thetransverse dimension “D_(H)” defined by the head 112, such that the pins106 _(A), 106 _(B) can be inserted through the bores 114 _(A), 114 _(B),114 _(C) and the slots 118 _(A), 118 _(B), 118 _(C), respectively, andthereby securely engage the rods 108 _(A), 108 _(B), 108 _(C). In theparticular embodiment of the constricting mechanism 100 seen in FIGS.1-6, the bores 114 _(A), 114 _(B), 114 _(C) receive the pins 106 _(A)included on the proximal member 102 _(A) while the slots 118 _(A), 118_(B), 118 _(C) receive the pins 106 _(B) included on the distal member102 _(B). In an alternate embodiment, however, the bores 114 _(A), 114_(B), 114 _(C) may receive the pins 106 _(B) included on the distalmember 102 _(B) while the slots 118 _(A), 118 _(B), 118 _(C) receive thepins 106 _(A) included on the proximal member 102 _(A).

The slots 118 _(A), 118 _(B), 118 _(C) extend along the rods 108 _(A),108 _(B), 108 _(C) to define a length “L_(S)” that is dimensioned toaccommodate relative movement between the rods 108 _(A), 108 _(B), 108_(C) and the pins 106 _(A), 106 _(B) which they receive duringmanipulation of the constricting mechanism 100, as described in furtherdetail below. Upon assembly of the constricting mechanism 100, the rods108 _(A), 108 _(B), 108 _(C) are interlaced such that an opening 120_(I) is defined therebetween. As seen in FIGS. 5-6, the rods 108 _(A),108 _(B), 108 _(C) are arranged such that the first end 116 _(A1) of therod 108 _(A) is positioned on top of the second end 116 _(B2) of the ofthe rod 108 _(B), the second end 116 _(A2) of the rod 108 _(A) ispositioned beneath the first end 116 _(C1) of the rod 108 _(C), and thefirst end 116 _(B1) of the rod 108 _(B) is positioned on top of thesecond end 116 _(C2) of the rod 108 _(C). However, other arrangements ofthe rods 108 _(A), 108 _(B), 108 _(C) in alternate embodiments of theconstricting mechanism 100 are also within the scope of the presentdisclosure.

Referring still to FIGS. 1-6, operation of the constricting mechanism100 will be described in conjunction with the surgical access system1000. Initially, i.e., prior to insertion of the surgical instrument“I”, the constricting mechanism 100 is in an open state (FIG. 5) inwhich the opening 120 _(I) defined between the rods 108 _(A), 108 _(B),108 _(C) is dimensioned to allow the surgical instrument “I” to passtherethrough substantially uninhibited. After insertion of the surgicalinstrument “I”, the clinician effectuates relative rotation between theproximal and distal members 102 _(A), 102 _(B), for example, by rotatingthe proximal member 102 _(A) relative to the distal member 102 _(B) inthe direction of arrow 1. To facilitate rotation of the proximal member102 _(A), in one embodiment, the proximal member 102 _(A) includes atactile member 122 that extends through the housing 1002 of the surgicalaccess system 1000 (FIG. 1) for manual engagement by the clinician.

Relative rotation between the respective proximal and distal members 102_(A), 102 _(B) causes the rods 108 _(A), 108 _(B), 108 _(C) to pivotabout the pins 106 _(A) extending through their respective bores 114_(A), 114 _(B), 114 _(C). As the rods 108 _(A), 108 _(B), 108 _(C)pivot, the pins 106 _(B) outwardly traverse the slots 118 _(A), 118_(B), 118 _(C) through which they extend in the direction indicated byarrow “X. The clinician continues to rotate the proximal member 102 _(A)until the constricting mechanism is transitioned into a constrictedstate (FIG. 6) in which the rods 108 _(A), 108 _(B), 108 _(C) define anarrowed opening 120 _(C) and engage an outer surface 12 of the surgicalinstrument “I”. The engagement of the rods 108 _(A), 108 _(B), 108 _(C)with the surgical instrument “I” substantially limits any transversemovement of the surgical instrument “I” within the constrictingmechanism 100, and thus, within the surgical access system 1000 (FIG.1).

As seen in FIG. 7, in one embodiment, the constricting mechanism 200 mayinclude rods 208 _(A), 208 _(B), 208 _(C) having scalloped portions 224_(A), 224 _(B), 224 _(C), respectively, to increase the surface area ofeach rod 208 _(A), 208 _(B), 208 _(C) that is in contact with thesurgical instrument “I” in the constricted state.

Referring again to FIGS. 1-6, to remove the surgical instrument “I” fromthe constricting mechanism 100, the clinician returns the constrictingmechanism 100 to the open state (FIG. 5) by rotating the proximal member102 _(A) in the direction of arrow 2. As the constricting mechanism 100transitions from the constricted state to the open state, the rods 108_(A), 108 _(B), 108 _(C) again pivot about the pins 106 _(A), and thepins 106 _(B) inwardly traverse the slots 118 _(A), 118 _(B), 118 _(C)in the direction indicated by arrow “Y”. The clinician continues torotate the proximal member 102 _(A) until the surgical instrument “I”can be withdrawn from the constricting mechanism 100. Alternatively,however, if the configuration and dimensions of the surgical instrument“I” allow, the clinician can simply withdraw the surgical instrument “I”in the proximal direction while the constricting mechanism 100 is in theconstricted state.

Referring now to FIGS. 8-9, in an alternate embodiment, the constrictingmechanism 300 may include a biasing member 326, such as a torsion springor the like, in mechanical cooperation with the respective proximal anddistal members 302 _(A), 302 _(B). The biasing member 326 applies abiasing force “F_(B)” to the respective proximal and distal members 302_(A), 302 _(B) which acts to normally bias the constricting mechanism300 towards the constricted state (FIG. 8). In this embodiment, as theclinician rotates the proximal member 302 _(A) in the direction of arrow1, the biasing force “F_(B)” is overcome, and the constricting mechanism300 transitions from the constricted state to the open state (FIG. 9).

To effectuate such rotation, the clinician can either manually displacethe tactile member 322 in the direction of arrow 1, as discussed abovewith respect to the embodiment seen in FIGS. 1-6, or alternatively, ifthe configuration and dimensions of the surgical instrument “I” allow,the clinician can simply force the surgical instrument “I” through theopening 320 _(C) defined by the constricting mechanism 300 in theconstricted state. As the surgical instrument “I” is forced distallythrough the opening 320 _(C), the surgical instrument “I” applies atransverse force “F_(T)” to the rods 308 _(A), 308 _(B), 308 _(C) thatis directed radially outward. The transverse force “F_(T)” causes therods 308 _(A), 308 _(B), 308 _(C) to pivot about the pins 306 _(A)extending through their respective bores 314 _(A), 314 _(B), 314 _(C).As the rods 308 _(A), 308 _(B), 308 _(C) pivot, the pins 306 _(B)inwardly traverse the slots 318 _(A), 318 _(B), 318 _(C) in thedirection of arrows “Y”, thereby effectuating relative rotation betweenthe respective proximal and distal members 302 _(A), 302 _(B) andenlarging the opening 320 _(C).

When the clinician seeks to remove the surgical instrument “I”, theclinician can either return the constricting mechanism 300 to the openstate (FIG. 9) by displacing the tactile member 322 in the direction ofarrow 1 and effectuating relative rotation between the respectiveproximal and distal members 302 _(A), 302 _(B), or alternatively, theclinician can simply withdraw the surgical instrument “I” from theconstricting mechanism 300 in the proximal direction, if theconfiguration and dimensions of the surgical instrument “I” allow.

In an alternate embodiment, the constricting mechanism may furtherinclude a motor and worm gear assembly in mechanical cooperation withthe constricting mechanism to regulate the reciprocal transitioningbetween the open and constricted states thereof. Employing a motor andworm gear assembly may allow the constricting mechanism to check thetransverse force applied to the rods by the surgical instrument uponinsertion such that the rods will not be spread apart.

Referring now to FIGS. 10-11, an alternate embodiment of theconstricting mechanism, referred to generally by reference number 400,will be discussed. The constricting mechanism 400 is substantiallysimilar to the constricting mechanism 100 that was discussed above withrespect to FIGS. 1-6, and accordingly, will only be discussed withrespect to its differences therefrom.

The constricting mechanism 400 includes a tubular sleeve 428 positionedwithin the opening 420 defined between the rods 408 _(A), 408 _(B), 408_(C). The tubular sleeve 428 is connected to the respective proximal anddistal members 402 _(A), 402 _(B) in any suitable manner, including butnot limited to integral formation therewith or the use of an adhesive.The tubular sleeve 428 defines a passageway 430 therethrough that isconfigured and dimensioned to receive the surgical instrument “I”. Inthe embodiment seen in FIGS. 10-11, the tubular sleeve 428 defines aninwardly tapered configuration to facilitate insertion of the surgicalinstrument “I” through the passageway 430. The tubular sleeve 428 may beformed of any biocompatible material that is at least semi-resilient innature, and in one embodiment, may be adapted to close the passageway430 in the absence of the surgical instrument “I”.

Following insertion of the surgical instrument “I”, the constrictingmechanism 400 is transitioned from the open state seen in FIG. 10 to theconstricted state seen in FIG. 11. During this transition, the rods 408_(A), 408 _(B), 408 _(C) deform the tubular sleeve 428 inwardly in thedirection of arrows “Y”. As the tubular sleeve 428 deforms, the tubularsleeve 428 engages the outer surface 12 of the surgical instrument “I”to form a substantially fluid-tight seal therewith. Accordingly, when inthe constricted state, the constricting member 400 serves not only torestrict transverse movement of the surgical instrument “I” insertedtherethrough, as described above with respect to the embodiment of FIGS.1-6, but also to substantially prevent the escape of insufflation gas.

As the constricting mechanism 400 is returned to the open state, theresilient nature of the material comprising the tubular sleeve 428allows the passageway 430 to re-open, thereby facilitating the removalof the surgical instrument “I” and the insertion of a subsequentinstrument, if necessary.

FIG. 12 illustrates an alternate embodiment of the constrictingmechanism, referred to generally by the reference umber 500. Theconstricting mechanism 500 is substantially similar to the constrictingmechanism 400 discussed with respect to FIGS. 10-11, but for theincorporation of a biasing member 526, such as a torsion spring or thelike. The biasing member 526 is in mechanical cooperation with therespective proximal and distal members 502 _(A), 502 _(B). As discussedabove with respect to the embodiment of the constricting mechanism 300seen in FIGS. 8-9, the biasing member 526 acts to normally bias theconstricting mechanism 500 towards the constricted state thereof inwhich the tubular sleeve 528 engages the outer surface 12 of thesurgical instrument “I” to form a substantially fluid-tight sealtherewith.

With reference now to FIGS. 13-15, another embodiment of theconstricting mechanism, referred to generally by reference number 600,will be discussed. The constricting mechanism 600 is substantiallysimilar to the constricting mechanism 100 discussed above with respectto FIGS. 1-6, and accordingly, will only be discussed with respect toits differences therefrom.

The constricting mechanisms 600 includes a seal member 632 defining anaperture 634 therethrough that is adapted to close in the absence of asurgical instrument “I” to substantially prevent the escaped ofinsufflation gas through the constricting mechanism 600. The seal member632 may include any structure suitable for this intended purpose,including but not limited to a tricuspid valve 636, as best seen in FIG.14, or a slit-valve. In the embodiment seen in FIGS. 13-15, theconstricting mechanism 600 includes a single seal member 632 that isassociated with the proximal member 602 _(A). However, the seal member632 may alternatively be associated with the distal member 602 _(B).Additionally, the present disclosure contemplates an embodiment of theconstricting mechanism 600 which includes multiple seal members 632i.e., first and second seal members, that are respectively associatedwith the proximal and distal members 602 _(A), 602 _(B).

Upon insertion of the surgical instrument “I” into the constrictingmechanism 600, the aperture 634 defined by the seal member 632 isenlarged and substantially conforms to the outer surface 12 of thesurgical instrument “I” such that a substantially fluid-tight seal isformed therewith. Accordingly, the constricting member 600 seen in FIGS.13-15 may be employed to not only restrict transverse movement of thesurgical instrument “I” upon insertion, as described above with respectto the embodiment seen in FIGS. 1-6, but also to substantially preventthe escape of insufflation gas.

FIG. 16 illustrates an alternate embodiment of the constrictingmechanism, referred to generally by reference number 700. Theconstricting mechanism 700 is substantially similar to the constrictingmechanism 600 discussed with respect to FIGS. 13-15, but for theincorporation of a biasing member 726, such as a torsion spring or thelike. The biasing member 726 is in mechanical cooperation with therespective proximal and distal members 702 _(A), 702 _(B). As discussedabove with respect to the embodiment seen in FIGS. 8-9, the biasingmember 726 acts to normally bias the constricting mechanism 700 towardsthe constricted state thereof to facilitate the secure engagement of asurgical instrument (not shown) to substantially limit transversemovement thereof.

Although the illustrative embodiments of the present disclosure havebeen described herein with reference to the accompanying drawings, theabove description, disclosure, and figures should not be construed aslimiting, but merely as exemplifications of particular embodiments. Itis to be understood, therefore, that the disclosure is not limited tothe precise embodiments described above. For example, each embodiment ofthe constricting mechanism discussed herein above has been described asincluding a proximal member that is rotated relative to a distal memberto transition the constricting mechanism between open and constrictedstates. It should be appreciated, however, that the constrictingmechanism may alternatively be caused to transition between the open andconstricted states by rotating the distal member relative to theproximal member. Various other changes and modifications may also beimplemented by one skilled in the art without departing from the scopeor spirit of the present disclosure

1. A surgical access device adapted for removable positioning within apercutaneous tissue tract, comprising: a housing; a constrictingmechanism positioned within the housing, the constricting mechanismincluding: proximal and distal members; and a plurality of longitudinalmembers positioned between the proximal and distal members, thelongitudinal members being interleaved so as to collectively define anaperture extending through the constriction mechanism, the proximal anddistal members being in mechanical cooperation to permit relativerotation therebetween such that the constricting mechanism isrepositionable between a first state, in which the aperture isconfigured and dimensioned to permit insertion of a surgical instrument,and a second state, in which the longitudinal members engage thesurgical instrument to limit transverse movement thereof; and an accesssleeve extending distally from the housing.
 2. The surgical accessdevice of claim 1, wherein the each of the plurality of longitudinalmembers is configured as a substantially linear rod.
 3. The surgicalaccess device of claim 2, wherein the proximal member includes a firstplurality of pins extending outwardly therefrom and the distal memberincludes a second plurality of pins extending outwardly therefrom, thefirst plurality of pins and the second plurality of pins beingconfigured and dimensioned for engagement with the plurality of rods. 4.The surgical access device of claim 3, wherein the first plurality ofpins and the second plurality of pins each correspond in number to thenumber of rods.
 5. The surgical access device of claim 3, wherein eachrod includes a bore formed at a first end and a slot formed at a secondend.
 6. The surgical access device of claim 5, wherein the firstplurality of pins and the second plurality of pins each include a stemportion terminating in a head, the head defining a transverse dimensiongreater than a transverse dimension defined by the stem portion.
 7. Thesurgical access device of claim 6, wherein each bore and each slotdefines a substantially identical transverse dimension greater than thetransverse dimension defined by the stem portion of each pin but lessthan the transverse dimension defined by the head of each pin such thatthe pins are securely engageable with the rods.
 8. The surgical accessdevice of claim 7, wherein the plurality of first pins are positionedwithin the bores of each of the plurality of rods and the plurality ofsecond pins are positioned within the slots of each the plurality ofrods such that relative rotation between the proximal and distal memberscauses the rods to pivot about the plurality of first pins as theplurality of second pins traverse the slots.
 9. The surgical accessdevice of claim 8, wherein the aperture extending through theconstricting mechanism defines a first transverse dimension when theconstricting mechanism is in the first state and a second, smallertransverse dimension when the constricting mechanism is in the secondstate.
 10. The surgical access device of claim 1, wherein at least oneof the first and second members includes a tactile member configured formanual engagement to facilitate relative rotation between the proximaland distal members.
 11. The surgical access device of claim 2, whereineach rod includes a scalloped portion configured and dimensioned toengage an outer surface of the surgical instrument.
 12. The surgicalaccess device of claim 1, wherein the constricting mechanism furtherincluding a biasing member in mechanical cooperation with at least oneof the proximal and distal members to normally bias the constrictingmechanism into the second state.
 13. The surgical access device of claim1, wherein the constricting mechanism further includes a sleeveconnected to the proximal and distal members, the sleeve defining apassageway therethrough configured and dimensioned to receive thesurgical instrument.
 14. The surgical access device of claim 13, whereinthe sleeve is forced into engagement with an outer surface of thesurgical instrument as the constricting mechanism is repositioned fromthe first state into the second state such that a substantiallyfluid-tight seal is formed between the constricting mechanism and thesurgical instrument.
 15. The surgical access device of claim 14, whereinthe sleeve is formed of a resilient material such that the passagewayenlarges as the constricting mechanism is repositioned from the secondstate into the first state to facilitate removal of the surgicalinstrument.
 16. The surgical access device of claim 1, wherein theconstricting mechanism further includes at least one seal memberassociated with at least one of the proximal member and the distalmember, the seal member being adapted to form a substantially fluidtight seal with the surgical instrument upon insertion.
 17. The surgicalaccess device of claim 1, wherein each of the plurality of longitudinalmembers includes a pair of opposing ends, the plurality of longitudinalmembers being arranged such that one of the opposing ends of each rod ispositioned distally of an adjacent rod in contact therewith, and theother of the opposing ends of each rod is positioned proximally of anadjacent rod in contact therewith.
 18. A method of manufacturing aconstricting mechanism for use with a surgical access device to limittransverse movement of a surgical instrument inserted therethrough,comprising the steps of: providing a proximal member including a firstplurality of pins extending outwardly therefrom; providing a distalmember including a second plurality of pins extending outwardlytherefrom; providing a plurality of rods including structure adapted toreceive one of the first plurality of pins and one of the secondplurality of pins; and positioning the rods between the proximal anddistal members such that the rods receive one of the first plurality ofpins and one of the second plurality of pins to permit relative rotationbetween the proximal and distal members such that the constrictingmechanism is repositionable between a first state, in which theconstricting mechanism is adapted to permit insertion of the surgicalinstrument, and a second state, in which the constricting mechanism isadapted to engage the surgical instrument to limit transverse movementthereof.
 19. The method of claim 18, wherein the step of positioning therods between the proximal and distal members includes interleaving theplurality of rods with each other such that the plurality of rodscollectively define an aperture extending through the constrictionmechanism for receipt of the surgical instrument.
 20. The method ofclaim 18, wherein the step of positioning the rods between the proximaland distal members includes positioning the plurality of first pinswithin bores included in each of the plurality of rods, and positioningthe plurality of second pins within slots included in each the pluralityof rods such that relative rotation between the proximal and distalmembers causes the rods to pivot about the plurality of first pins asthe plurality of second pins traverse the slots.